This invention relates generally to radar antennas and more particularly to a line source array in which the beam may be electronically scanned over a limited angular range.
Small angle electronic scanning of a radar beam is required in many surveillance applications, including personnel and vehicle detection, fire registration, projectile tracking, etc. One such antenna has been developed by Rockwell International and has been described in an article entitled "Inexpensive Phased Array Opens Up New Radar Applications", by Richard T. Davis, which article appeared in the publication entitled Microwaves in August, 1975, at pages 15 and 16. The phased array antenna disclosed therein is based on the series ferrite scan principle in which a waveguide having series connected ferrite phase shifters inserted lengthwise between each radiating element has current applied which induces a longitudinal magnetic field in the ferrite. Electronic beam scanning is effected by controlling the propagating velocity or phase shift per unit length of the ferrite loaded waveguide.
Accordingly, it is an object of the present invention to provide an improved phased array operated in accordance with the series ferrite scan principle.